well you can use different atfs without any problems you just have to read the bottle to see if it meets the mercon v spec it is actually fairly easy to find this is actually the case with most auto manufacturers they all have their own different fluid specs and make it sound like if you use anything else your tranny with blowwink wink it is actually pretty funny when you see them use different manufacturers transmissions and still use their own fluid without problems most of the specs actually overlap with each other and if you check different brands of fluid youll see they meet most manufacturers specs